1. Field of the Invention
The present invention relates to an operational control device, an operational control method, a program and a storage medium thereof, for a plurality of power consumption systems in a power supply system for supplying electric power to the plurality of power consumption systems, such as processing equipments which provide desired processes to semiconductor wafers or the like.
2. Background Art
In general, for manufacturing semiconductor integrated circuits, liquid crystal devices or the like, various processing equipments are used for repeatedly subjecting materials to be processed, such as semiconductor wafers, LCD substrates and the like, to various processes, including oxidation, film-forming, diffusion, annealing, reforming and the like.
In such a case, it is common to prepare a plurality of the same or different processing equipments for subjecting the wafers or LCD substrates to desired processes in succession and completing the products, and operate each of the processing equipments in parallel to enhance the throughput. For wafers and LCD substrates, since heating and plasma processes are mainly performed, each processing equipment consumes relatively a large amount of electric power. In addition, power supply equipments for supplying electric power to those units are relatively expensive. Therefore, if only one power supply equipment is used to supply electric power to a plurality of processing equipments, it is usual to prepare a power supply equipment that meets the power capacity corresponding to “the normal rated power of each processing equipment (the maximum power)×the number of units” in order to make the power supply equipment as small as possible.
However, all processing equipments are not always driven at the normal rated power. In fact, the time for which they are driven at the normal rated power is relatively short. In the case of a processing equipment for performing a heating process, this unit is used for a temperature raising step for elevating the wafer temperature and also used for a step for maintaining a constant temperature, thus making quite a large difference in the electric power consumption between the two steps. In the temperature raising step, the electric power consumption becomes large approximately to the normal rated power, while in the temperature maintaining step, depending on the types of processes, the electric power consumption is relatively small, ranging from 10 to 60% of the rated power. Accordingly, the above prior art power supply equipments should have significantly large margin of the power capacity, thus leading to increase in the cost of such power supply equipments and increase in the contract rate to the electric power company.
To address these disadvantages, methods for controlling the increase in the cost of power supply equipments have been disclosed in the following Patent Documents 1 and 2, and the like. For example, the method disclosed in the Patent Document 1 comprises detecting and monitoring electric power generated from an electric power supply equipment; comparing the detected electric power to a reference value before individual power consumption system starts a new step; and judging whether or not the new step is to start based on the comparison.
Documents Cited:
    Patent Document 1: TOKUKAIHEI No. 9-56068, KOHO    Patent Document 2: TOKUKAIHEI No. 8-181110, KOHO
In such prior art methods, upon starting a step, judgment of whether or not to start the step was determined by comparison between actually detected electric power and a reference value obtained by referring to the amount of power consumption in a step which requires the maximum power consumption. However, since these prior art methods did not consider any change in the amount of power consumption over time for each processing equipment, so once a process was started, such a change in the amount of power consumption along the proceeding of the process of each processing equipment was not controlled enough.